Synergistic copper nanoparticles and adjacent single atoms on biomass-derived N-doped carbon toward overall water splitting

The rational design of effective heterogeneous electrocatalysts with an appropriate electronic structure and active sites is crucial for efficient overall water splitting. Atomic-level active site manipulation can not only result in a highly efficient activity but also provide an in-depth understanding of the catalytic mechanism. Herein, we construct a synergistic copper catalyst containing single atoms and nanoparticles on biomass-derived N-doped carbon nanosheets, which provides high-density active centers and precise regulation of local environments, achieving low overpotentials of 200 mV for the oxygen evolution reaction and 216 mV for the hydrogen evolution reaction at 10 mA cm(-2), respectively. Moreover, a small cell voltage of 1.65 V is attained to achieve a current density of 10 mA cm(-2) for overall water splitting. This work provides a novel strategy for constructing a non-precious atomic-site catalyst and demonstrates the potential of precise tailoring of the structural heterogeneity for electrochemical water splitting.